Each week seems to bring new claims that the Affordable Care Act (a.k.a. Obamacare) — which begins enrollment for coverage on health insurance exchanges on Oct. 1 — will bring calamity. In many ways, this furor is reminiscent of Medicare's beginnings in 1966. That law, passed in 1965, had just a year before it went live. There were plenty of naysayers and fears of potentially calamitous roadblocks.

For starters, many physician groups called for a national boycott. That never took place. Many physicians quickly realized that whether or not this was "socialized" medicine, Medicare would pay for visits by many Americans who had not been able to afford care. The number of people 65 and older using physician services jumped dramatically, and doctors and patients both benefited.

Another concern was that the Medicare law required hospitals receiving Medicare dollars to take all comers, thus desegregating U.S. hospitals in one fell swoop. Federal workers and even the National Guard were put on call in July 1966 should disaster strike. But all was quiet, and Medicare contributed substantially to speeding up the desegregation of healthcare.

Nearly half a century later, Medicare is — along with Social Security — one of the two most popular government programs ever, and well accepted by the medical community.

In its day, Medicare was in some ways even more controversial than the Affordable Care Act is today, since it was so different from the rest of the healthcare system. What's different is that Obamacare's opponents, more than Medicare's, seem unwilling to help make the law work. This frenzied and often misleading opposition might seem comical if millions of people who stand to benefit weren't being put at risk. No wonder the polls find that people are confused.

What's going on here? It's partly political theater in a society so deeply divided that "the other side" never gets credit for doing a good job or even having good intentions. And it's partly a peculiarly American resistance to changes in government programs buttressed by overblown fears. One fear is that Obamacare is bad for business and will lead to unemployment. Yes, UPS announced it would no longer cover spouses of workers who could get coverage elsewhere. But while a few companies are using the new law as an excuse to do what they planned to do anyway, there is little evidence that many are. In fact, if employers do cut benefits, Obamacare offers options for good insurance at affordable prices.

The new insurance marketplaces that will help individuals who lack employer coverage have also been attacked as forcing people into buying excessive insurance. Some states that could have helped shape these marketplaces to better fit their needs declined to cooperate with the new law. But isn't setting up a level playing field where insurers must offer a recognized set of benefits in ways that allow competition the very heart of what a capitalist society owes its citizens? And mandating that people buy insurance is a lot like requiring that everyone contribute to Medicare, which few Americans now see as controversial.

Another fear is that insurance costs will be higher. But announced rates for these new plans are turning out to be very reasonable. Many expected California's rates to come in high (with some opponents projecting a 66% increase, for example). In fact, most Californians will pay about the same rates in 2014 as in 2013, and many will be eligible for subsidies that make care even more affordable. Only those who currently skimp on coverage in the risky hope that they'll remain healthy indefinitely may have to spend more for better plans.

The latest dust-up is over "navigators" — people hired to help buyers understand their choices and choose plans. Coincidentally, this program is modeled on those for Medicare beneficiaries that have worked well. The red flags raised about privacy issues should be lowered because such counselors will know only what individuals choose to tell them if they seek help.

Chances are, when the law takes effect and the sky doesn't fall, people will accept that both the requirement that everyone have insurance and the rules governing how insurance is offered are improvements to our health system — much as they accepted Medicare.

Marilyn Moon is director of the American Institutes for Research's Center on Aging and a former public trustee for the Social Security and Medicare trust funds.